Total braking system failure?

[Raro]

Ahh, so you think the ABS module (which is still Bosch) has such a simple failure mode? 12V power isn't clean enough so it disables brakes? Or noisy communications cause it to block brakes? Geez man. Do you think every engineer besides yourself is incompetent? This isn't the Wild West. There are standard that automobile components have to live up to.

I didn’t say it would be a simple failure mode, or that it has anything to do with incompetent engineering on anyone’s part. It’s clear that the OP had some major electrical/electronic issue affecting hardware in different areas of the car systems before the issue.

if every automotive project always lives up to standard then why did VW have thousands of cars sitting for months because of a software issue, shouldn’t it all have been figured out during initial engineering And qualification?

How was takata, a engineer company founded in the 1930s not able to engineer, test and qualify an airbag without figuring out that moisture would affect it over the years and kill people when it went off?

How could GM and Delphi not engineer a ignition lock that wouldn’t lead to 124 deaths?

How did Boeing, a aerospace juggernaut for decades, not realized that their master event timer on their starliner capsule would go haywire during the launch to the space station?

It’s got nothing to do with a Wild West attitude, bottom line is complex systems fail in complex ways.

I once worked on a race car project with a professional driver testing the car, he came in after a run and said the car stuck at full throttle, We checked the pedal assembly and it was working just fine, smooth as can be, the logging data supported it, both fly by wire throttle potentiometers were showing that the pedal had been depressed. People on the team directly started talking about how the guy made a mistake, confused the brake and accelerator etc but he was adamant.

We ended up tracking down an issue with the return spring binding up under heavy vibrations down the straight, locking up the pedal.

Moral of the story is don’t always assume its user error, it’s could be a complex error that is easier to blame on the user than digging into and finding other potential causes for.

 

[Daniel in SD]

I didn’t say it would be a simple failure mode, or that it has anything to do with incompetent engineering on anyone’s part. It’s clear that the OP had some major electrical/electronic issue affecting hardware in different areas of the car systems before the issue.

if every automotive project always lives up to standard then why did VW have thousands of cars sitting for months because of a software issue, shouldn’t it all have been figured out during initial engineering And qualification?

How was takata, a engineer company founded in the 1930s not able to engineer, test and qualify an airbag without figuring out that moisture would affect it over the years and kill people when it went off?

How could GM and Delphi not engineer a ignition lock that wouldn’t lead to 124 deaths?

How did Boeing, a aerospace juggernaut for decades, not realized that their master event timer on their starliner capsule would go haywire during the launch to the space station?

It’s got nothing to do with a Wild West attitude, bottom line is complex systems fail in complex ways.

I once worked on a race car project with a professional driver testing the car, he came in after a run and said the car stuck at full throttle, We checked the pedal assembly and it was working just fine, smooth as can be, the logging data supported it, both fly by wire throttle potentiometers were showing that the pedal had been depressed. People on the team directly started talking about how the guy made a mistake, confused the brake and accelerator etc but he was adamant.

We ended up tracking down an issue with the return spring binding up under heavy vibrations down the straight, locking up the pedal.

Moral of the story is don’t always assume its user error, it’s could be a complex error that is easier to blame on the user than digging into and finding other potential causes for.

Yeah, seems more likely that it's hard to recognize that unassisted friction brakes are working when the car is already decelerating at 0.2g from regenerative braking.

On a side note, if the accelerator was stuck wouldn't he have had to press the brake and wouldn't that have also been logged?

 

[CertLive]

I didn’t say it would be a simple failure mode, or that it has anything to do with incompetent engineering on anyone’s part. It’s clear that the OP had some major electrical/electronic issue affecting hardware in different areas of the car systems before the issue.

if every automotive project always lives up to standard then why did VW have thousands of cars sitting for months because of a software issue, shouldn’t it all have been figured out during initial engineering And qualification?

How was takata, a engineer company founded in the 1930s not able to engineer, test and qualify an airbag without figuring out that moisture would affect it over the years and kill people when it went off?

How could GM and Delphi not engineer a ignition lock that wouldn’t lead to 124 deaths?

How did Boeing, a aerospace juggernaut for decades, not realized that their master event timer on their starliner capsule would go haywire during the launch to the space station?

It’s got nothing to do with a Wild West attitude, bottom line is complex systems fail in complex ways.

I once worked on a race car project with a professional driver testing the car, he came in after a run and said the car stuck at full throttle, We checked the pedal assembly and it was working just fine, smooth as can be, the logging data supported it, both fly by wire throttle potentiometers were showing that the pedal had been depressed. People on the team directly started talking about how the guy made a mistake, confused the brake and accelerator etc but he was adamant.

We ended up tracking down an issue with the return spring binding up under heavy vibrations down the straight, locking up the pedal.

Moral of the story is don’t always assume its user error, it’s could be a complex error that is easier to blame on the user than digging into and finding other potential causes for.

Kind of interesting how VW are now working their way into a lot of arguments lately here. That ID line is making its way into a lot of comparisons and its always good to have a sturdy platform to start from. Software can be updated as a Tesla owners there is a lot of that. No glass roofs flying off those yet... But you are right to put it into the context of a complicated machine and 1 in 1000 might have an issue that has 100,000 per car chance of showing up in said situation. From a technical side I am fascinated to try and work out even if all power is lost the break could not be pressed be it with some force. Its just the way it works in my head like power steering if it was lost sure its a lump all of a sudden but you should still have the ability to steer. Can it suffer from that much back pressure on the pedal? Yea it might be like a rock to press but the breaks would still touch the discs? Just one of those things I really want to know the SC answer for out of intense curiosity.

 

[Raro]

Yeah, seems more likely that it's hard to recognize that unassisted friction brakes are working when the car is already decelerating at 0.2g from regenerative braking.

On a side note, if the accelerator was stuck wouldn't he have had to press the brake and wouldn't that have also been logged?

Yes, but this testing was done at Pocono, a 2 mile oval track, depending on the freshness of your tires you will only be lifting the throttle and not using the brakes, luckily he kept the car on the track and then just killed the ignition at corner exit, the pedal then came unstuck so he could drive it into the pits.

 

[Krugerrand]

How could this happen?

See below:

The car was acting strange from the first moment this morning.

1. erratic window roll down behavior when I opened the front door
2. dark/blank screen upon entry
3. warning message: vehicle hold feature unavailable
4. warning message: 12 v battery must be replace soon

It behooves person, whether they own a Tesla or a Bentley or a Gremlin, to heed warning signs that the vehicle may be experiencing a mechanical issue. Call me crazy but back in the day when the oil light came on in the car, I went out on a limb and checked to see if I had an oil leak and enough oil in the car. And when the battery gage fell below 12v, I checked not only the battery but also the alternator. Of course we all had that one friend who didn’t and then was like, ‘I dunno!?’ FYI, You’re that friend.

 

[one2many]

Back in the old days (sorry) it was not common for everyone I
knew to have the brake pedal go to the floor. Breaks gone and air in
the lines. Well after $50 in parts and my two 6 packs of beer everyone
was happy and a little safer. Battery warning on an EV, holy mother
of TNT's. carry on

 

[CertLive]

The troops have arrived....

 

[iwannam3]

forces the shoes outward against the drum. If I remember correctly. Also, I think that only works in a forward direction. At least that is what it felt like in the drum brakes I drove.

the front typically had 2 pistons and shoes that self energized and the rear had one piston that pushed one shoe forward and one shoe backward so you has 1/4 of the shoes self energizing in reverse.

 

[Pilot1226]

Yikes man, the 12V needs more than a moment's notice to tell you it's no good.

 

[rsg123]

Another reason to never skip leg day.

 

[wornhall]

The physical braking system in my Model 3 completely failed this morning.
I didn't realize it until I got on the freeway ramp and almost hit the car in front of me.
Luckily, the regen braking was enough to slow the car down.

The brake pedal felt like it was in a locked position at the top of its range. Could not depress the pedal at all.

This was an absolute critical safety failure.

The car was acting strange from the first moment this morning.
1. erratic window roll down behavior when I opened the front door
2. dark/blank screen upon entry
3. warning message: vehicle hold feature unavailable
4. warning message: 12 v battery must be replace soon

After I rebooted the car, I drove off to working thinking it was nothing.
After realizing the brake failure, I got off the next freeway and exit and drove it back home safely.
With the road side assistance tech on the phone, I tried rebooting the car with no luck.
Then, tried powering the car off via the lcd screen and waiting a couple of minutes seems to solve the issue this time.

The car is now with the Tesla service center.

How could this happen? This was extremely dangerous and I feel very fortunate.
I could have easily found out the hard way at 70+ mph.

Hope this never happens again to me or anybody else, ever.

 

[wornhall]

I disagree with the nearly hyperbolic notes on your brake problem reporting. You did NOT nearly crash; the regenerative braking brought you to a safe stop. Obviously, it was not as severe as you made it out to be. So what if it did happen at 70mph? You continued your drive to your home without incident. You did not mention the fact that emergency braking is invoked by depressing the right wand button to "p" (park) the car. You must have missed that in you manual. Even a new driver knows that in the event of power loss, the brake pedal is extremely hard to depress, but it is available. The symptoms you described in the morning, typically indicate the 12V battery is dead or dying... the manuals. Final analysis; you knew something was wrong, but you drove on without testing the basic systems, namely the braking system.

 

[Riodriver]

Nearly 2 weeks ago, I had a similar msg after the last update. My pedal kind of danced below my foot when I first depressed it and acted squirrelly for the next few seconds before the problem disappeared. I got a sudden low 12v battery warning and a couple others at the time.

I drove it several times before getting the battery replaced when my headlights stopped working (tech admitted the headlight failure is a “feature”). I have a 2018 M3.

 

[Pilot1226]

Does the 12V battery actually enable (or disable if it fails) the braking?

 

[az erik]

So interestingly enough. I have had 2 FFE's (Ford Focus Electrics) and both, a couple times a year throw 12v battery messages. However the car, once started, provides a solid 13.2V to all the 12v things it could complain about. The battery message usually happens when I'm backing out of the driveway or within a couple feet of driving away. Rebooting the car has always resolved it. If I was sitting in my model 3 and driving away with the above warning I too would probably just keep driving. Because "there should be a bigger warning light" if the brakes were to just, you know, not work. I still think it ridiculous that there would be 400ish volts of mega battery and the lead acid 12volt battery has to take all this abuse and be the Achilles to the car.
The FFE's I have/had just roast the 12volt battery by slam charging the thing once it "starts". You can turn the cars off and hear the lead battery boiling. I can't speak to how the 12v charging works for a Tesla as I'm in delivery hold mode. (Delivery center says come get it, wife says hold off there hot rod)

 

[Riodriver]

Final analysis; you knew something was wrong, but you drove on without testing the basic systems, namely the braking system.

It would be great if we all read the manual from cover to cover however the manual is dynamic, many of us are busy, and consumers (esp. non-owners) have reasonable expectations of the road worthiness and predictability of a car (especially if it drives). Hyperbolic or not, the original poster was trying to make us aware of the problem, not malign Tesla.

Can you refer us to the manual pages discussing the common vehicle behavior when the 12v goes out? Or what exactly that braking warning should mean if seen once?

 

[Makofoto]

Just like my colleagues VW Tiguan. She had to invoke the Lemon Law, after it required an all new Brake SYSTEM and new Steering Column, within a month of buying it!

 

[MikeHolliday]

Every Car made in the last 53 years. has a Dual Master Cylinder setup...

"By 1967, it was mandated by the Federal Government that all vehicles use a dual-brake master cylinder, with separate circuits in case of the failure of a line or other issue."

Yes, even Tesla's have Dual Brake Master Cylinders... With Dual Brake Master Cylinders it is literally impossible to loose both front and rear brakes. Someone would have to cut a brake line on the front and on the rear of the car to loose total braking. There are even two brake fluid reservoirs in every car made along with the two master cylinders. You may have to put all of your weight into the peddle to stop, but it will stop.
And yes, Tesla's has a Dual Master Brake setup...

May people are so spoiled by power brakes that they have no idea as to the energy required to press a peddle when power is lost.

I personally own a number of 50 year old cars including a Triumph TR6. I say BS, to a total brake failure. You may have to put your entire weight if you are small person, when the power asisst goes out, but it will stop.

 

[Cleo-n-Company]

What mystifies me about many of the responses on this forum is why so many individuals are Tesla apologists. Total brake failure... the driver didn't know what they were doing... and another array of excuses. I ask this as a Model S owner who has watched my P85+ start to immolate in a series of electrical failures. Why don't more of you folks push the company to accept its faults and address them? Not trying to start a fight - but I sometimes struggle... sometimes laugh with the Tesla "aura." Many folks leave their common sense in the frunk... seriously...

 

[MikeHolliday]

If it was a toltal brake failure, I say hang Tesla. But I may not be an expert on Teslas, but I know car braking systems and Tesla is required to build theirs in compliance with Federal Law. They cannot sell their cars without a Dual-Master Brake Cylinder setup.

I own a Model Y and yes it has a Dual-Master Brake Cylinder setup.